Part:BBa_K624032

Magnetospirillum magneticum AMB-1

Facultative anaeroabic magnetotactic bacterial species, Magnetospirillum magneticum AMB-1. Grow in liquid MSGM (Magnetic Spirillum Growth Medium), or on MSGM agar plate.Like E. coli, AMB-1 also grows in liquid medium, and this medium is called Magnetic Spirillum Growth Medium (MSGM). In the medium, we added nutrient, iron source (supplying AMB-1 in magnetite formation within magnetosomes), vitamin, and mineral solution.

NCBI: [http://www.ncbi.nlm.nih.gov/sites/entrez?Db=genome&Cmd=ShowDetailView&TermToSearch=19021 whole genome sequence]

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]

We also refered to an original article published by Chen-Dong Yang, et al., which added Polypeptone and Yeast extract into MSGM and added L-cysteine instead of sodium thioglycolate, a mixture called En-rich MSGM. In <<Effects of growth medium composition, iron sources and atmospheric oxygen concentrations on production of luciferase-bacterial magnetic particle complex by a recombinant Magnetospirillum magneticum AMB-1,2001>> said that MSGM enriched with L-cysteine, yeast extract' and polypeptone could enhance BMP (Bacterial Magnetic Particles) productivity. Addition of yeast extract had no effect on BMP (Bacterial Magnetic Particles) production and polypeptone only improved the final cell density and therefore slightly improved BMP (Bacterial Magnetic Particles) production, whereas L-cysteine induced cell growth!

MSGM's ingredients

(In grams per liter)

●Succinic acid             0.74 g
●KH2PO4                    0.68 g
●Sodium nitrate            0.12 g
●Sodium thioglycolate      0.1 g
●[http://2011.igem.org/File:Wolfe_vitamin.pdf *Wolfe's vitamin solution]  10 ml(stock)
●[http://2011.igem.org/File:Wolfe.pdf *Wolfe’s mineral solution]  5  ml(stock)
●Ferric quinate solution   2  ml(0.27 g of FeCl3 and 0.19 g of quinic acid in 100 ml water)
 Adjust pH to 7.0 with NaOH

En-rich MSGM's ingredients

(In grams per liter)

●Succinic acid             0.74 g
●KH2PO4                    0.68 g
●Sodium nitrate            0.12 g
●*Wolfe's vitamin solution  10 ml(stock)
●*Wolfe’s mineral solution  5  ml(stock)
●Ferric quinate solution   2  ml(0.27 g of FeCl3 and 0.19 g of quinic acid in 100 ml water)
●L-cysteine                0.005%(Instead of sodium thioglycolate) 
●Yeast extract             0.01%
●Polypeptone               0.02%
Adjust pH to 7.0 with NaOH

Strict anaerobic conditions have been thought to facilitate BMP (Bacterial Magnetic Particles) production in AMB-1 cells. To induce AMB-1 forming magnetosome, we have to control low O2 concentration.

Growth Curve Of AMB-1

We measure AMB-1's growth under OD565, which is the best absorption wavelength for AMB-1. For electroporation operation, it is important to find out the log phase, since it’s the best time for electroporation. By keeping AMB-1 in "log phase" (approximately 3~6 days in Enrich-MSGM, 7~10 days in MSGM), best results of electroporation are achieved. And after seven days, the bacterium would go into stationary phase. During the phase, the growth slows as a result of nutrient depletion and accumulation of toxic products. Growth rate and death rate of bacterium is best likely to meet equilibrium in this stage.